This invention relates to pet litter boxes with an automatic ventilation or exhaust system and more particularly to a self-contained ventilated litter box particularly adapted for cats.
Automatic cat or pet activated litter boxes have been proposed including that shown in the patent of Roberts U.S. Pat. No. 5,140,948, issued Aug. 25, 1992. The arrangements shown in this and similar prior art references for the operation or activation of the ventilating system depend upon physical contact by the pet with a component, such as a sensing switch, or the moving of a door, for the purpose of activating the ventilating system. In other instances, the ventilating system is simply turned on and run continuously.
An initiation device, such as an electric switch, which must be triggered by the pet may be obtrusive as well as undependable. Further, fan induced ventilating systems are anything but quite, particularly in the confines of a litter box enclosure, and the immediate activation of such a system may frighten an animal and thus may discourage the animal's proper use of the litter box.